Best place to be a founder outside of the US?

I've been living in the US on a nonimmigrant work visa for a few years and I'm thinking of my next moves. I'd like to start a startup, but my whole immigration status is tied to working for my employer and nobody else, including myself. I like living here, and it's clearly the strongest place in the world for tech, but it's too disheartening to stay here long-term with no prospect of even getting an immigrant visa beyond a long, long process in which many things can go wrong and you need to start from scratch. With all the news about immigration restrictions, I think a lot of non-American entrepreneurs and professionals are starting to question whether the US is the best place for them.

Despite everything, the US (especially San Francisco, New York, and Seattle) is by far the best place to start a startup. It's the only place where it's deeply ingrained in the culture to take big risks, to aim for the sky, to think in terms of billions instead of just millions. Most crucially this relates to funding, where the deepest-pocketed and most risk-tolerant investors (angels, VCs) are in the US.

But as the US becomes more unfriendly for foreign entrepreneurs, I don't see any other country picking up the torch and nurturing the same startup-friendliness that the US has to attract ambitious people. China and Israel feel like the only countries with a nearly equally-healthy startup scene, but I expect those are hard places to live in for someone with no ties to the country. But where else would a person go? Toronto? Europe? (I'm a Canadian/EU dual citizen so these are appealing to me.) Dubai? Singapore? Thailand?